JP6071191B2 - Sealed package and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sealed package and a method for manufacturing the same. More specifically, the present invention relates to a hermetic package in which the surface of a heat-shrinkable film is printed and a method for manufacturing the same.

  Conventionally, as a method for wrapping processed products such as fish meat, livestock ham / sausage, cheese, sheep gourd, wairo, etc., these packages are filled into a tubular film molded body in which a resin film is sealed in an envelope, and the upper end and A method of ligating (sealing) the lower end is widely used.

  By the way, there are cases where printing is performed on a resin film for the purpose of improving the design of the package or giving the consumer an explanation of the product. However, in surface printing, printing may be peeled off due to heat, rubbing, or the like in boiling, retorting, etc., and there is a problem that the commercial value is remarkably impaired. Therefore, for the purpose of improving the fixing property of the ink, the surface is subjected to corona treatment, frame treatment or the like, or a special material is used.

  Patent Document 1 describes a method for producing a retort printing container, in which a polyolefin sheet made of a specific polyolefin or an outer surface of a container is subjected to a frame treatment so that a wetting index is 45 dyne / cm or more, and then printing is performed. .

  Furthermore, Patent Document 2 describes a multilayer film for packaging which can be printed on a surface and is made of a co-extrusion method, which is composed of at least two layers of a sealing layer (D) located on the surface opposite to the outermost layer (A). ing.

Japanese Patent Laid-Open No. 1-1141934 JP 2004-98536 A

  However, the techniques described in Patent Documents 1 and 2 have problems such as insufficient adhesion of printing ink for surface printing and time-consuming management of surface treatment. Furthermore, due to special surface treatments such as frame treatment and corona treatment, the amount of bleeds increases, and slipperiness due to stickiness tends to occur. Thereby, in the conventional technique, the running property of the film becomes unstable, and as a result, the sealing property tends to become unstable.

  The problem to be solved by the present invention is to provide a sealed package having a printed part on the film surface capable of achieving excellent resistance to heat, rubbing and the like in boil and retort treatment, and a method for producing the same.

  As a result of earnestly examining the means for solving the above problems, the present inventors have provided a printing portion in a specific region of the heat-shrinkable film to be used, so that the surface of the heat-shrinkable film can be subjected to corona treatment or frame treatment. It has been found that the printing has excellent resistance to heat, rubbing and the like in the boil and retort processing even without special treatment. More specifically, when the heat-shrinkable film is made into a cylindrical shape, both side edges are overlapped and the overlapped portion is heat sealed, one side edge is located inside the cylindrical molded body, and the cylindrical shape The other side edge portion is positioned outside the molded body. The side edge portion (film outer ear piece) located on the outside is usually a portion that serves as a knob when the sealed package is opened. By printing in advance on the surface of the heat-shrinkable film and covered with this film outer ear piece, the film outer ear piece protects the printing from heat and rubbing in the boil and retort processing, and makes the printing difficult to peel off. The present inventors have found that this is possible. Since it is not necessary to perform a special treatment such as corona treatment or frame treatment on the surface of the heat-shrinkable film, both excellent sealing properties and design properties can be achieved.

The present invention provides the following (1) to (7).
(1) A cylindrical film formed by laminating both side edges of a heat-sealable strip-shaped heat-shrinkable film, and fusing the overlapped part in the longitudinal direction of the film to form a seal part;
A sealing member that seals both openings of the tubular film filled with the contents;
A film outer ear piece consisting of one side edge of the heat-shrinkable film and projecting into a strip shape outside the cylindrical film;
A printing section in which printing is performed in the area covered with the film outer ear piece on the surface of the tubular film;
A hermetically sealed package.
(2) The heat shrinkable film has a heat shrinkage rate at 120 ° C. of 15 to 40% in both the vertical and horizontal directions, and a heat shrinkage rate at 90 ° C. of 5 to 30% in both the vertical and horizontal directions. The sealed package according to (1).
(3) The hermetically sealed package according to (1) or (2), wherein a scar is processed on the edge of the film outer ear piece.
(4) The heat-shrinkable film is a sealed package according to any one of (1) to (3), which is transparent or translucent.
(5) A printing process in which printing is performed on one side edge of a heat-sealable strip-shaped heat-shrinkable film to form a printing part;
A cylinder making process in which the heat-shrinkable film is curved so that the surface on which the printing part is formed is on the outside and the both side edges of the film are overlapped so that the other side edge covers the printing part;
A cylindrical molded body is formed by fusing the overlapping portions of both side edge portions in the longitudinal direction of the film so as to form a film outer ear piece that protrudes outside in a band shape and covers the printing portion. Fusing process to obtain
A filling step of filling the cylindrical shaped body with the contents;
A sealing step for sealing both openings;
A method for manufacturing a sealed package comprising:
(6) The method for producing a hermetic package according to (5), wherein printing is performed by an inkjet method in the process of conveying the heat-shrinkable film.
(7) The method further includes a transporting step of transporting the film by a plurality of rollers in contact with the surface of the heat-shrinkable film among the plurality of rollers, and the roller that contacts the surface on which the printing unit is formed is larger than the width of the printing unit. The method for producing a hermetic package according to (5) or (6), which is a stepped roller having a wide groove.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing packaging body which has the printing part which can achieve the outstanding tolerance with respect to the heat | fever, rubbing, etc. in a boil and a retort process on a film surface, and its manufacturing method can be provided. More specifically, in the present invention, characters, patterns, and symbols are freely printed in a predetermined area of the heat-shrinkable film at the time of manufacturing the sealed package, and the printed portion is covered with a film outer ear piece for protection. To do. Thereby, the outstanding tolerance of the printing part with respect to the heat | fever, rubbing, etc. in a boil and a retort process can be achieved, and the external appearance, appearance, and the sealing package body which is excellent in the design property are realizable. Moreover, since it is not necessary to perform a special treatment such as a corona treatment or a frame treatment on the surface of the heat-shrinkable film, an excellent sealing property of the sealed package can be achieved.

It is a perspective view which shows typically a mode that the sealed package which concerns on one Embodiment of this invention is opened. It is the II-II sectional view taken on the line of the sealed package shown in FIG. It is a figure which shows typically the principal part structure of an automatic filling packaging machine. It is a perspective view which shows an example of a stepped roller. It is a perspective view which shows typically the process of printing on the surface, conveying a heat-shrinkable film with a roller.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified, and the dimensional ratio in the drawing is not limited to the illustrated ratio. Further, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist thereof.

<Sealed package>
As shown in FIGS. 1 and 2, the sealed package 10 according to the present embodiment overlaps both side edges of a belt-shaped heat-shrinkable film, and a substantially central portion of the overlapped portion is predetermined in the longitudinal direction of the film. It consists of a tubular film 2 formed by heat-sealing with a width to form a seal portion 3, a sealing member 4 that seals both ends of the tubular film 2, and the other side edge of the tubular film 2. A film inner ear piece 2a protruding in a strip shape on the inner side, a film outer ear piece 2b formed of one side edge of the cylindrical film 2 and protruding in a band shape on the outer side, and a film outer ear piece 2b on the surface of the cylindrical film 2 And a printing unit 7 on which printing is performed in the area covered with the. The sealed package 10 contains the contents 8. Here, fish meat, livestock ham, or sausage is illustrated as the contents 8, but cheese, sheep gourd, sea bream, etc. may be accommodated.

  As shown in FIG. 1, characters “↑ can be opened from anywhere here” are printed on the printing unit 7. The print unit 7 is provided in the vicinity of the seal unit 3 along the seal unit 3, and is provided not in the exposed surface of the sealed package 10 but in an area covered with the film outer ear piece 2 b. The surface of the tubular film 2 (the surface of the printing unit 7) and the inner surface of the film outer ear piece 2b are in contact with each other in a tight state. For this reason, even if the sealed package 10 is boiled or retorted, it is possible to sufficiently suppress the characters on the printing unit 7 from being peeled or thinned by heat or rubbing. Note that the printing unit 7 is not limited to one printed with characters, but may be one printed with symbols or patterns.

  The width of the printing unit 7 (W1 in FIG. 1) is preferably 3 to 10 mm, and more preferably 5 to 8 mm. By setting the width W1 to 3 mm or more, the size of the characters and symbols of the printing unit 7 can be sufficiently recognized by the user. On the other hand, by setting the width W1 to 10 mm or less, the heat shrinkage for covering the printing unit 7 Increase in material cost of the adhesive film (film outer ear piece 2b) can be suppressed.

  If the width | variety (W2 of FIG. 1) of the film outer ear piece 2b can cover the printing part 7, there will be no restriction | limiting in particular, Preferably it is 5-20 mm, More preferably, it is 10-15 mm.

  As shown in FIG. 1, when the scar processing 9 is given to the edge part of the film outer ear piece 2b, it is preferable that the printing part 7 is covered with the remaining part where the scratch processing 9 is not given. Scratch processing means processing for forming a group of minute scars at the end of the film, and is intended to facilitate tearing of the film and improve openability. If it is made for the part which gave the scar process 9 and the printing part 7 not to overlap, inflow of the hot water from a scar group in a boil or retort processing, and the rubbing between the print part 7 and the scar group of the scar process 9 are carried out. Since it can prevent, it is preferable. Moreover, since the visibility of the printing part 7 does not fall, it is preferable.

  The tubular film 2 is made of a belt-like heat-shrinkable film, and is preferably transparent or translucent to visible light from the viewpoint of the visibility of the printing unit 7. Since the tubular film 2 has heat shrinkability, the sealed package 10 is finished in a tight state by boiling or retorting. At the same time, the printing unit 7 and the film outer ear piece 2b contract and come into contact with each other in a tight state, so that they are difficult to shift. Further, since the film outer ear piece 2b is in close contact with the printing unit 7 to protect it, the printing is hardly peeled off.

  The heat shrinkage rate of the heat shrinkable film is preferably 15% or more at 120 ° C. in both the longitudinal direction and the transverse direction, and the heat shrinkage rate at 90 ° C. is preferably 5% or more. Since the film satisfying this condition has sufficient tension, the printing on the printing unit 7 is difficult to peel off. Further, the heat shrinkage rate of the heat shrinkable film is preferably 40% or less at 120 ° C. or 30% or less at 90 ° C. in both the longitudinal direction and the transverse direction. A film that satisfies this condition is moderately shrunk and difficult to be loaded on the seal portion 3 of the hermetic package 10, so that it is difficult to break the bag. In addition, the heat shrink rate of a heat-shrinkable film means the value measured by the measuring method based on ASTM D-2732.

  The effect of the tubular film 2 having heat shrinkage can be obtained even during the boil or retort treatment. For example, in order to make it difficult to peel off when performing retort processing at 120 ° C. for 20 minutes, the process of raising the water temperature to 120 ° C. as well as that the sealed package 10 is in a tight state at 120 ° C. However, it is preferable that the sealed package 10 is in a tight state. As a representative point of the temperature in this temperature raising process, 90 ° C. can be used. As described above, when the thermal shrinkage rate at 90 ° C. is 5% or more in both the vertical direction and the horizontal direction, the tight state of the sealed package 10 is maintained, and the contact between the printing unit 7 and the film outer ear piece 2b becomes difficult to shift. Since the protection of the printing portion is maintained, the printing is hardly peeled off even during the temperature rising process.

  The heat shrinkage rate of the heat-shrinkable film can be controlled by the stretching ratio or the stretching temperature during film production, or the heat treatment during or after stretching. Specifically, the thermal shrinkage rate is increased by increasing the draw ratio or lowering the stretching temperature or the heat treatment temperature. On the other hand, the thermal shrinkage rate tends to decrease by decreasing the stretching ratio or increasing the stretching temperature or the heat treatment temperature.

  Specific examples of the heat-shrinkable film include, for example, VDC / VC (vinylidene chloride / vinyl chloride copolymer), VDC / MA (vinylidene chloride / methyl acrylate copolymer), HIPS (impact polystyrene), PVDC ( Examples thereof include polyvinylidene chloride), PVC (polyvinyl chloride), PA (polyamide), PE (polyethylene), PP (polypropylene), EVOH (ethylene-vinyl alcohol copolymer), and the like.

  As described above, the heat-shrinkable film may be a single-layer film or a multilayer film in which a plurality of films are laminated. From the viewpoint of imparting various functions, for example, a multilayer film in which a sealant film is laminated on one side and / or both sides of a base film is preferably used. In addition, the multilayer film includes a film in which an adhesive layer, a gas barrier layer, or the like is interposed between each essential layer. This type of multilayer film includes, for example, a dry laminating method in which two or more films are bonded together, an extrusion laminating method in which the other resin composition is melt-extruded and laminated on one film, and a resin composition. It can be manufactured by a known method such as a co-extrusion method in which a laminate is formed by cooling after extrusion. In the case of a multilayer film, the film preferably includes at least one layer having gas barrier properties. More specifically, a gas barrier multilayer film comprising at least three layers of a core layer made of a polyamide polymer or a PVDC polymer and both outer layers made of a polyolefin polymer having a melting point of 90 to 170 ° C. is preferable. The polyamide-based polymer that forms the barrier layer has oxygen barrier properties and pinhole resistance, and the polyolefin-based polymer that is the seal layer has heat-sealing properties and water vapor barrier properties.

  Examples of the polyolefin polymer include an ethylene homopolymer, an ethylene polymer such as ethylene and an α-olefin copolymer having 4 to 8 carbon atoms, a propylene homopolymer, a copolymer of propylene and ethylene, propylene and Examples thereof include a propylene polymer such as a copolymer with an α-olefin having 4 to 8 carbon atoms and a copolymer of propylene, ethylene and an α-olefin having 4 to 8 carbon atoms. These polyolefin polymers may be random copolymers or block copolymers. Specific examples of the α-olefin having 4 to 8 carbon atoms include 1-butene, 4-methyl-1-pentene, 1-pentene, 1-hexene, 1-octene, and the like. Not. These polymers may be used alone or in combination of two or more. Of these, propylene-based polymers such as ethylene-α-olefin copolymers, propylene-ethylene copolymers, and propylene-ethylene-1-butene copolymers can be preferably used because they are relatively inexpensive.

  From the viewpoint of stretchability, the polyolefin polymer preferably has a value represented by weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.5 to 3.5, more preferably 1.5. ~ 3.0.

  The polyamide polymer preferably contains an aromatic polyamide polymer. Here, the aromatic polyamide polymer means crystalline nylon (polyamide) having an aromatic ring in the main chain, and specific examples thereof include, for example, polycondensation of metaxylylenediamine and adipic acid. Polymetaxylylene adipamide (nylon MXD6) obtained by the above, polycondensate of metaxylylenediamine, adipic acid and isophthalic acid, and the like.

  Aromatic polyamide-based polymers have better gas barrier properties, lower water absorption, less decrease in gas barrier properties during water absorption, and better pinhole resistance than aliphatic nylons such as nylon 6 and nylon 6/66. In addition to the above properties, the stretchability and molding processability are also good, so that it is preferably used.

  In the multilayer film in which the polyolefin polymer and the polyamide polymer are laminated, if the adhesive force between the films is not sufficient, an adhesive layer can be interposed as necessary. Examples of the resin used as the adhesive layer include acid-modified polyolefin. Among them, ethylene homopolymer, ethylene-α-olefin copolymer or ethylene-propylene copolymer is an acid such as maleic acid or an anhydride thereof. An acid-modified product modified with a product is preferred.

  The PVDC-based polymer contains 80 to 97% by mass of vinylidene chloride and means a copolymer of vinylidene chloride and vinyl chloride or a copolymer of vinylidene chloride and methyl acrylate. The weight average molecular weight of the PVDC polymer is preferably 80,000 to 130,000, more preferably 100,000 to 125,000.

  PVDC polymers include liquid plasticizers such as dibutyl sebacate, acetyl tributyl citrate, glycerin diacetomonolaurate, epoxidized soybean oil, epoxidized linseed oil, bisphenol A diglycidyl ether, epoxidized octyl stearate, Liquid additives such as heat stabilizers typified by epoxy compounds such as epoxidized palm oil can be added, and the total amount of the liquid additives is preferably in the range of 1 to 10% by weight. Also, organic or inorganic pigments, spherical or amorphous silicon dioxide, calcium carbonate, magnesium oxide represented by pear finish, lubricants represented by fatty acid amide, etc. can be added. The amount is preferably in the range of 0.01 to 1.0% by weight. Depending on the application, a surfactant such as sorbitan fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene fatty acid ester and the like may be added in an amount of 0.1 to 1.0% by weight.

  The thickness of the heat-shrinkable film is not particularly limited and can be arbitrarily set. However, considering the use of fish meat, livestock ham, sausage, etc., the total thickness (total thickness) of the heat-shrinkable film Is preferably 30 to 50 μm.

  In general, the occurrence frequency of bag breakage during retort processing and the easy-openability during opening are in a trade-off relationship, and when the thickness is increased, the occurrence frequency of bag breakage during retort processing tends to decrease. On the other hand, when the thickness is reduced, it tends to be easily opened with an appropriate force at the time of opening. It is preferable that the total thickness is 30 to 50 μm because both of these characteristics can be maintained in a well-balanced manner.

  The heat shrinkable film preferably has a heat shrinkage stress at 120 ° C. (hereinafter also referred to as “ORS 120 ° C.”) of 1.0 to 3.5 MPa in both the vertical direction and the horizontal direction. When the sealed package 10 using this heat-shrinkable film was boiled or retorted, the heat-shrinkable film was fitted to the contents 8 and the contents 8 were diminished during long-term storage. However, the generation of wrinkles derived from the slack of the heat-shrinkable film can be effectively suppressed.

  Considering the suppression of wrinkle generation during the long-term storage and the balance of the sealing characteristics, the ORS 120 ° C. of the heat-shrinkable film is more preferably 1.5 to 3.0 MPa in both the vertical direction and the horizontal direction. "ORS120 degreeC" here means the value measured based on ASTM D-1504.

  The width of the seal portion 3 is preferably 0.5 to 3.0 mm. If the width of the seal portion 3 is 0.5 mm or more, the peeling failure of the seal portion 3 is reduced, and if the width of the seal portion 3 is 3.0 mm or less, the easy-openability can be sufficiently secured.

  For the sealing member 4, after the synthetic resin film is focused, a method of applying ultrasonic waves, high frequency, or heat to the converging part and fusing it, or a synthetic resin wire is wound around the converging part, and the wound portion is fused. Known methods such as a method of wearing, a method of winding a metal wire such as aluminum, and a method of using these in combination, as conventionally performed, can be employed.

<Method for producing sealed package using automatic filling and packaging machine>
A method for manufacturing the sealed package 10 using the automatic filling and packaging machine 100 will be described in detail. The manufacturing method of the hermetic package 10 is a series of processes including a printing process, a cylinder manufacturing process, a heat sealing process, a filling process, and a sealing process. To produce a sealed package 10.

  The sealed package 10 can be easily obtained by using a known automatic filling and packaging machine, for example, “ADP (registered trademark)” manufactured by Asahi Kasei Chemicals Corporation and printing means. Hereinafter, an example of a manufacturing method of the sealed package 10 will be described in detail with reference to FIG. The automatic filling and packaging machine 100 shown in FIG. 3 includes a film supply unit 11, a printing unit 21, a filling unit 31, a cylinder making unit 41, a heat seal unit 51, and a sealing unit 61.

  The film supply unit 11 includes a plurality of rollers 11a to 11l, feed rollers 12a and 12b, and a drive mechanism (not shown), and forms a belt shape from the original roll 13R according to the drive of the drive mechanism and the feed rollers 12a and 12b. The heat shrinkable film 13 is continuously supplied. The supply speed of the heat-shrinkable film 13 is usually about 10 to 60 m / min, and the type, thickness, rigidity, melting point of the heat-shrinkable film 13 to be used, the material and viscosity of the contents 8 to be filled, etc. It is set appropriately according to The film supply means 11 continuously supplies the heat-shrinkable film 13 to a later-described tube-making folder 42 via rollers 11a to 11l (conveying step).

  The heat-shrinkable film 13 supplied from the film supply means 11 is printed by the printing means 21 before being supplied to the tube making folder 42 (printing process). The printing unit 21 has a print head 22 that performs printing by an inkjet method, and characters and patterns are printed with a predetermined width on one side edge of the heat-shrinkable film 13 by the print head 22 (see FIG. 5). .

  Among the rollers 11a to 11l shown in FIG. 3, the rollers 11d, 11f, 11i, and 11k are in contact with the surface of the heat-shrinkable film 13 on which the printing unit 7 is provided. Characters or the like printed on the heat-shrinkable film by the print head 22 may be peeled off when touching the roller before the ink solvent dries. For this reason, it is preferable that the rollers 11d, 11f, 11i, and 11k are stepped rollers having grooves wider than the width W1 of the printing unit 7 so that the printing unit 7 does not directly touch the roller. A roller 11d shown in FIG. 4 is an example of a stepped roller. The roller 11d has a groove 11G on the roller surface 11F. By using a part of the rollers of the film supply means 11 as stepped rollers, the heat shrinkable film 13 can be conveyed without the printing unit 7 coming into contact with the rollers, as shown in FIG.

  The heat-shrinkable film 13 is preferably subjected to scratch processing in advance on the side edge on the side opposite to the side edge on which printing of the heat-shrinkable film 13 is performed at the time of film production.

  Next, the heat-absorbing reduced film 13 is formed into a cylindrical shape by the cylinder-making means 41 (cylinder-making process). The tube making means 41 has a tube making folder 42 formed by winding a metal piece of a predetermined shape into a substantially spiral shape. The heat-absorbing shrink film 13 is guided from the upper surface opening of the tube-making folder 42 to the lower-surface opening, and in the process, the heat-absorbing shrink film 13 follows the substantially spiral structure in the tube-making folder 42 and is formed into a cylindrical shape. It becomes a cylindrical body which has the overlapping part 2 which was curved and the both side edge part was overlapped. At this time, in the overlapping portion 2, the entire printing portion 7 is covered with the side edge portion (film outer ear piece 2 b) of the heat-absorbing shrink film 13.

  A part of the overlapping portion 2 of the cylindrical body formed in the cylinder making process is melted and sealed by the heat seal means 51 (fusion process). In the fusing process, the heat-shrinkable film 13 is heat-sealed by a suitable means depending on the material of the heat-shrinkable film 13. For example, when the heat-shrinkable film 13 is a PVDC single layer film, the application nozzle 52 can be brought into contact with the heat-shrinkable film 13 and a high frequency of 20 to 50 MHz can be applied for heat sealing. In the case where the surface layer of the heat-shrinkable film 13 is a multilayer film of a polyolefin polymer, heat sealing can be performed by blowing hot air from the application nozzle 52 with the interval between the application nozzle 52 and the film being 0.5 to 2 mm.

  When performing heat sealing, the overlapping portion 2 is heat-sealed at a position closer to the film inner ear piece 2a than the printing portion 7 so that the sealing portion 3 does not overlap the printing portion 7, thereby forming a substantially cylindrical tubular molded body. To do. Depending on the heat seal state of the overlapping portion 2, the heat seal state is adjusted by heating the seal portion 3 with the internal heating mandrel 54 or cooling the seal portion 3 with the cold air nozzle 53 or the internal cooling mandrel 55. can do.

  Next, the contents 8 are filled into the cylindrical molded body by the filling means 31 (filling step). The filling means 31 includes a filling nozzle 32. The filling nozzle 32 penetrates through the tube making folder 42 and is arranged substantially concentrically with the tube making folder 42. The cylindrical molded body includes a filling nozzle 32, and the contents 8 are fed directly from the filling nozzle 32 into the heat-sealed cylindrical molded body. The cylindrical molded body filled with the contents 8 is sandwiched between the feed rollers 12 a and 12 b and transferred to the sealing means 61.

  The cylindrical molded body filled with the contents 8 is sealed by the sealing means 61. The sealing unit 61 includes squeezing rollers 62a and 62b and sealing mechanisms 63a and 63b. The cylindrical molded body filled with the contents 8 is pressed from the outside at predetermined intervals by the squeezing rollers 62a and 62b, the contents 8 in the pressed portions are pushed away, and the areas pressed by the sealing mechanisms 63a and 63b Are focused and sealed. The sealing process in the sealing mechanisms 63a and 63b is a technique of applying ultrasonic waves, high frequency or heat to the converging part of the heat-shrinkable film 13 and fusing it, synthetic resin or metal for the converging part of the heat-shrinkable film 13 A known method such as a method of caulking and ligating a manufactured wire or the like, or a method of using them together is adopted.

  By the above sealing treatment, both end portions of the cylindrical molded body are sealed, whereby the sealed package 10 is manufactured. In addition, you may divide | segment the sealed packaging body 10 by which both ends were sealed into each sealed packaging body 10 simultaneously with a sealing process, or in the subsequent cutting process.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited only to these Examples.

The measurement methods and evaluation methods for various performances are described below.
(1) Thermal contraction rate It measured by the method based on ASTM D-2732. Specifically, the thermal shrinkage rate was measured when immersed in hot water at 120 ° C. for 20 minutes under a pressure of 0.25 MPa, and was defined as the thermal shrinkage rate at 120 ° C. Moreover, the thermal contraction rate at the time of being immersed in 90 degreeC hot water for 10 minutes under atmospheric pressure was measured, and it was set as the 90 degreeC thermal contraction rate. In the measurement of the heat shrinkage rate, measurements were made in the vertical direction and the horizontal direction, and the average value of each of the five test results was used as the heat shrinkage rate.
(2) Retort suitability For 300 sealed packages, the number of prints peeled off was measured for sealed packages that had been subjected to a retort treatment at 120 ° C. for 20 minutes under the condition that the heated can pressure gauge pressure was 0.25 MPa. Evaluation was made according to the following criteria.
○: The number of prints peeled off was less than 3 ×: The number of prints peeled off was 3 or more (3) Measurement of crystal melting temperature (melting point) Melting point was measured using Pyrris Diamond DSC manufactured by Perkin Elmer. . In the measurement, the temperature of the sample was raised from 10 ° C. to 200 ° C. at 10 ° C./min, held at 200 ° C. for 1 minute, then cooled to 10 ° C. at 10 ° C./min, and held at 10 ° C. for 1 minute. The temperature corresponding to the peak value of the crystal melting curve when the temperature was raised again at 10 ° C./min was read as the melting point.
(4) Thermal contraction stress (ORS120 ° C)
The heat shrink stress at 120 ° C. of the heat shrinkable film was measured by a method based on ASTM D 1504. In the measurement at ORS 120 ° C., a strip test piece (length: 150 mm, width: 10 mm) obtained by cutting a heat-shrinkable film was held between a pair of clips connected to a U gauge. The sample was immersed in a silicone oil having a bath temperature of 120 ° C. for 5 minutes, and the maximum heat shrinkage stress at this time was measured with a U gauge. In the measurement of the heat shrinkage stress, measurement was made in the longitudinal direction and the transverse direction, and the average value of each of the five test results was used as the heat shrinkage stress.
(5) Abbreviations of Resins The abbreviations and names of the resins used in the examples and comparative examples are summarized in Table 1.

[Example 1]
After melt coextrusion using an annular 5-layer die with the layer structure shown in Table 2, it was solidified with cold water at about 15 ° C. to produce a tube-shaped unstretched original fabric having a total thickness of about 1100 μm. Next, this unstretched original fabric was biaxially stretched at a stretching temperature of about 120 ° C. and stretched at a stretching ratio of about 5 times in the machine direction and about 6 times in the transverse direction by an inflation method, and then heated at 90 ° C. A multilayer film having a final thickness of about 40 μm was obtained by heat treatment with a roll. The heat-shrinkable film of Example 1 was produced by winding up the obtained multilayer film, cutting it to 100 mm in width while unwinding it, applying scratch processing to the end, and winding it up again.

  Next, fish meat was filled using a hot air sealing type automatic filling and packaging machine ("ADP (registered trademark)" manufactured by Asahi Kasei Chemicals Corporation). At that time, printing was performed on the surface layer (A) of the heat-shrinkable film of Example 1 using an inkjet printing apparatus (RX-HD260J manufactured by Hitachi Industrial Equipment Systems Co., Ltd.). Specifically, after printing on the surface layer (A), the surface layer (A) is curved in a cylindrical shape through a tube-making folder so that the outer peripheral surface constitutes the outer peripheral surface, and the printing portion is covered with one side edge portion. As shown, the surface layer (E) was superposed on the surface layer (A). In this state, a hot air was blown from the surface layer (A) side, and heat sealing was performed on the envelope, thereby producing a tubular molded body having a folding width of 40 mm. Subsequently, fish sausage raw surimi was filled from a filling nozzle into a cylindrical molded body, and then both ends were ligated and sealed with an aluminum wire to obtain a fish sausage sealed package having a length of 200 mm. Table 2 shows the evaluation results of the heat shrinkage rate and retort suitability evaluation.

[Example 2]
In the layer structure shown in Table 2, after biaxial stretching at a stretching ratio of about 5 times in the longitudinal direction and about 6 times in the transverse direction at a stretching temperature of about 110 ° C., heat treatment was performed with a heating roll at 75 ° C. A fish sausage hermetically sealed package was obtained in the same manner as in Example 1 except that the heat-shrinkable film produced in this manner was used. Table 2 shows the evaluation results of the evaluation of heat shrinkage and boil suitability.

[Example 3]
As a PVDC polymer, as a plasticizer for 100 parts by mass of vinylidene chloride-vinyl chloride copolymer (vinylidene chloride content / vinyl chloride content = 89% by mass / 11% by mass, weight average molecular weight 125,000). 3 parts by weight of dibutyl sebacate, 2.5 parts by weight of acetyltributyl citrate, 2 parts by weight of epoxidized soybean oil as a heat stabilizer, 0.1 parts by weight of amorphous silicon dioxide having an average particle size of 5μ as a satin finish 0.1 parts by weight of stearamide as a lubricant, Pigment Yellow 139 (product name: GraPhtol Yellow H2R manufactured by Clariant Japan Co., Ltd.) as pigment, 0.2 parts by weight of Pigment RED166 (trade name CROMOPHTAL manufactured by Ciba Specialty Chemicals Co., Ltd.) Scarlet RN) 0.1 parts by mass , Added and mixed.

  The resulting mixture was extruded into a tube with a melt extruder, supercooled in a cold water bath at about 10 ° C., passed through 35 ° C. water, stretched at 30 ° C., 3.0 times in the vertical direction, and 4.0 in the horizontal direction. A tubular film obtained by performing double inflation biaxial stretching was folded with a pinch roll to produce a flat long double-ply film original having a width of about 1 m and a target thickness of 40 μm. Then, it cut | judged to 100 mm in width while unwinding, the scar process was given to the edge part, and the heat-shrinkable film of Example 3 was produced by winding up again.

  Next, fish meat was filled using a high-frequency seal type automatic filling and packaging machine ("ADP (registered trademark)" manufactured by Asahi Kasei Chemicals Corporation). At that time, printing was performed on the surface of the heat-shrinkable film of Example 3 using an inkjet printing apparatus (RX-HD260J, manufactured by Hitachi Industrial Equipment Systems Co., Ltd.). Specifically, after printing on the front surface, the printing surface is curved in a cylindrical shape through a tube-making folder so that the outer peripheral surface constitutes the outer peripheral surface, and the printing portion is covered with one side edge portion. The edges were overlapped. In this state, a tubular molded body having a folding width of 40 mm was produced by heat sealing the envelope. Subsequently, fish sausage raw surimi was filled from a filling nozzle into a cylindrical molded body, and then both ends were ligated and sealed with an aluminum wire to obtain a fish sausage sealed package having a length of 200 mm. Table 3 shows the evaluation results of the heat shrinkage rate and retort suitability evaluation.

[Comparative Example 1]
Using the resins shown in Table 2, a tube-shaped unstretched original fabric having a total thickness of about 440 μm was prepared. Next, this unstretched original fabric was biaxially stretched at a stretching temperature of about 125 ° C. and stretched at a stretching ratio of about 12 times, which was about 3 times in the longitudinal direction and about 4 times in the transverse direction by an inflation method, and then heated at 100 ° C. A multilayer film having a final thickness of about 40 μm was obtained by treatment with a roll. Thereafter, a heat-shrinkable film of Comparative Example 1 was obtained in the same manner as Example 1. Next, a fish sausage hermetically sealed package was obtained in the same manner as in Example 1 except that the inkjet printing was provided in an area not covered with the film outer ear piece. Table 2 shows the evaluation results of the heat shrinkage rate and retort suitability evaluation.

[Comparative Example 2]
Comparative Example 1 except that the resin shown in Table 2 was subjected to corona treatment on the surface layer (A) so that the wetting tension was 45 mN / m, and the inkjet printing was provided in an area not covered with the film outer ear piece. In the same manner as above, a fish sausage sealed package was obtained. Table 2 shows the evaluation results of the heat shrinkage rate and retort suitability evaluation.

  According to the present invention, even if the surface is not subjected to a special treatment, it is possible to sufficiently suppress the peeling of the print due to heat and rubbing in the boil or retort treatment, and provide a sealed package with excellent aesthetics and high commercial value. it can. This sealed package can be used widely and effectively in food and other various packaging applications.

DESCRIPTION OF SYMBOLS 2 ... Cylindrical film, 2a ... Film inner ear piece (one side edge part), 2b ... Film outer ear piece (the other side edge part), 3 ... Seal part, 4 ... Sealing member, 7 ... Printing part, 8 ... Contents: 9 ... Scar processing, 10 ... Sealed package, 11d, 11f, 11i, 11k ... Roller (stepped roller), 13 ... Heat-shrinkable film.

Claims (6)

A cylindrical film formed by superimposing both side edges of a heat-sealable strip-shaped heat-shrinkable film, and fusing this overlapping part in the longitudinal direction of the film to form a seal part;
A sealing member that seals both openings of the tubular film filled with contents;
A film outer ear piece which consists of one side edge of the heat-shrinkable film and protrudes in a strip shape outside the tubular film;
A printing section in which the area on the surface of the tubular film is covered with the film outer ear piece and the area is printed;
Bei to give a,
The heat-shrinkable film has a heat shrinkage rate at 120 ° C. of 15 to 40% in both the vertical and horizontal directions, and a heat shrinkage rate at 90 ° C. of 5 to 30% in both the vertical and horizontal directions. Packaging body. The hermetically sealed package according to claim 1, wherein a scar is processed on an edge of the film outer ear piece. The sealed package according to claim 1 or 2 , wherein the heat-shrinkable film is transparent or translucent. A printing step in which printing is performed on one side edge of a heat-sealable strip-shaped heat-shrinkable film to form a printing portion;
A cylinder making process in which the heat-shrinkable film is curved so that the surface on which the printing part is formed is on the outside, and both side edges of the film are overlapped so that the other side edge covers the printing part;
In order to form a film outer ear piece that protrudes outside in a band shape and covers the printing portion, the overlapping portion of the side edge portions is fused in the longitudinal direction of the film to form a seal portion to form a cylindrical shape A fusion process for obtaining a molded body;
A filling step of filling the cylindrical shaped body with the contents;
A sealing step for sealing both openings;
Bei to give a,
The heat-shrinkable film has a heat shrinkage rate at 120 ° C. of 15 to 40% in both the vertical and horizontal directions, and a heat shrinkage rate at 90 ° C. of 5 to 30% in both the vertical and horizontal directions. A method for manufacturing a package. The manufacturing method of the sealed package body of Claim 4 which performs the said printing by an inkjet system in the process in which the said heat-shrinkable film is conveyed. A transport step of transporting the film by a plurality of rollers in contact with the surface of the heat-shrinkable film;
The method for manufacturing a hermetic package according to claim 4 , wherein a roller that contacts the surface on which the printing unit is formed among the plurality of rollers is a stepped roller having a groove wider than a width of the printing unit. .

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